Class: Luhnar

Inherits:
Object
  • Object
show all
Defined in:
lib/luhnar.rb,
lib/luhnar/version.rb

Constant Summary collapse

VERSION = 
"1.0.1"

Class Method Summary collapse

Class Method Details

.compute(number) ⇒ Object

returns checkdigit for number as integer



6
7
8
9
10
11
12
13
14
 
# File 'lib/luhnar.rb', line 6

def self.compute number
  p = true
  -number.to_s.chars.to_a.reverse.inject(0) do |s,c| 
    d  = c.to_i
    d *= 2 if p
    p = !p
    s + d + d/10
  end % 10
end